Rubidium fluoride (RbF) is the

fluoride Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), whose salts are typically white or colorless. Fluoride salts typ ...

salt of

rubidium Rubidium is the chemical element with the symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have a density higher ...

. It is a cubic

crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

with

rock-salt Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

structure. There are several methods for synthesising rubidium fluoride. One involves reacting

rubidium hydroxide Rubidium hydroxide is the inorganic compound with the formula RbOH. It consists of rubidium cations and an equal number of hydroxide anions. It is a colorless solid that is commercially available as aqueous solutions from a few suppliers. Like ot ...

with

hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include th ...

: :RbOH + HF → RbF + H₂O Another method is to neutralize

rubidium carbonate Rubidium carbonate, Rb2CO3, is a convenient compound of rubidium; it is stable, not particularly reactive, and readily soluble in water, and is the form in which rubidium is usually sold. Preparation This salt can be prepared by adding ammonium c ...

with hydrofluoric acid: :Rb₂CO₃ + 2HF → 2RbF + H₂O + CO₂ Another possible method is to react rubidium hydroxide with

ammonium fluoride Ammonium fluoride is the inorganic compound with the formula NH4F. It crystallizes as small colourless prisms, having a sharp saline taste, and is highly soluble in water. Like all fluoride salts, it is moderately toxic in both acute and chronic o ...

: :RbOH + NH₄F → RbF + H₂O + NH₃ The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with

halogen The halogens () are a group in the periodic table consisting of five or six chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). In the modern IUPAC nomenclature, this group is ...

s: :2Rb + F₂ → 2RbF

References

* Rubidium compounds Fluorides Alkali metal fluorides Rock salt crystal structure {{inorganic-compound-stub